LTE-A Module Series
EM121R-GL Hardware Design
EM121R-GL Hardware Design 26 / 80
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Run Time
DRX OFF ON OFF
ON OFF ON OFF ON OFF
Figure 3: DRX Run Time and Current Consumption in Sleep Mode
The following part of this section describes the power saving procedure and sleep mode entrance of the
module.
If the host supports USB suspend/resume and remote wakeup function, the following two conditions must
be met to make the module enter sleep mode.
⚫
Execute
AT+QSCLK=1
command to enable the sleep mode.
⚫
The host’s USB bus, which is connected to the module’s USB interface, enters suspend state.
The following figure shows the connection between the module and the host.
USB Interface
USB Interface
Module
Host
GND
GND
Figure 4: Sleep Mode Application with USB Remote Wakeup
The module and the host will wake up in the following conditions:
⚫
Sending data to module through USB will wake up the module.
⚫
When module has a URC to report, the module will send remote wake-up signals via USB bus to
wake up the host.